190d belt tensioner noisy at low rpm.

[rosenfe]

i was told by my mechanic that belt tensioner on my 87 190d is worn and causing nosise at idle.what does it take to replace it,where exactly is it?

[muleears]

Not familiar with your exact setup but if it is similar to my 603 there is a small shock absorber opposite the tensioner spring. This shock wears and the bushings on the ends wear out and rattle at idle. I know on mine it needs replacement about every 50K miles. Simple to replace and the shock is about $40. Hope this helps.

[sasquatchgeoff]

Also replace the spring while your at it. Make sure the pivot pin is torqued to 90Nm as well.

[rosenfe]

my engine has 2 shocks in the front by fan,is the tensioner that round thing between them,do i have to take belt off to replace it,shocks look ok

[sasquatchgeoff]

Shock can "look" OK but be totally worn out. Do a search in the DIY section for "belt tensioner" - there should be several how-to's. Better yet, obtain a copy of the FSM on disc.

Shock on left side, spring on right. You will need the tire tool or a gigantic screwdriver to release tension, then do the change out.

[hsmith]

Make sure you have a diagram of how the belt goes back on.

Hugh Sr